How to measure loss of string tension

[julian1]

There is a device to do it.
Comments are welcome
Did anybody use it before?

----> a quote from a seller below
Gamma ATS ERT 300 Tenniscomputer

Price: $169.00

Product Details

With the ERT 300 Tenniscomputer, you'll know when it's time to restring your racquet. The display shows current string bed stiffness (dynamic tension), indicating the power and aggressiveness of play and alerts when it is time to restring. Provides highly precise measurement through an electronic simulation of the ball impact. Pocket-sized, cordless, and easy to use. Works with any racquet and string type. Battery operated.

Approx. 110 x 50 x 25mm
Instruction manual and reference card included
Batteries included

amma ATS ERT 300 Tenniscomputer

Price: $169.00

Product Details

With the ERT 300 Tenniscomputer, you'll know when it's time to restring your racquet. The display shows current string bed stiffness (dynamic tension), indicating the power and aggressiveness of play and alerts when it is time to restring. Provides highly precise measurement through an electronic simulation of the ball impact. Pocket-sized, cordless, and easy to use. Works with any racquet and string type. Battery operated.

Approx. 110 x 50 x 25mm
Instruction manual and reference card included
Batteries included

[stumphges]

I would look at the racquetTune app if you have an iDevice of some kind. The developer is an engineer from Sweden and he recently validated the app using a load cell affixed to his racquet frame.

After entering string material, gauge and string pattern, one gives the stringbed a rap with a screwdriver or something. The app records the resulting "ping", analyzes the frequency, and spits out both string tension and stringbed stiffness (as the ERT does) with high accuracy. And it's only a couple of bucks.

If you've got a camera on your device, the app will also perform a swingweight calculation by photographing the swings of a suspended racquet and then calculating the swing frequency from the photo sequence. (If you know the swing frequency, balance and static weight then you can calculate swingweight. Many people use the at-home method of measuring swing frequency with a stopwatch, but it's time-intensive to do this with high accuracy. The app makes it simple.)

Swingweight is crucial to matching racquets. Before the at-home method became popular, a player had to take his frames to a customizer or shop that had a $2000-plus Babolat RDC or Prince diagnostic machine. With this app you can determine swingweight very easily and then use online calculators (the app also has a calculator) to figure out where and how much lead to apply to match two frames. It's now possible for any player to customize and precisely match their frames at home.

[julian1]

Usage of a device

Please see post #1 of

http://tt.tennis-warehouse.com/showthread.php?t=360414&highlight=genesis+gut